改进波形相似叠加算法的音频时长调整

针对波形相似叠加算法在处理高采样率音频时效率低的缺点，提出由短时均值包络到细化波形的逐步匹配方法. 首先基于短时均值包络进行粗匹配，在此基础上细化包络，进行再匹配以实现音频时长调整. 该算法降低了计算量，提高了运算效率. 在进行音频时长调整过程中，还利用音频的优化低能量率特征参数动态调整分析窗长度，实验表明这种处理方法对混合音频的处理效果有很大改进.

Time-Scale Modification of Audio Signal Using Improved WSOLA Algorithm

To improve efficiency of the waveform similarity overlap-and-add (WSOLA) algorithm in audio signal processing at high sampling rate, this paper proposes a matching method that is progressively performed from the short time mean envelop to the signal waveform. We compute a rough matching envelop based on short time mean envelop, and then perform an exact waveform matching for time-scale modification of the audio signal. The algorithm reduces computation complexity, and improves efficiency with good outcome. In addition, the length of analysis windows is dynamically adjusted based on the modified low energy ratio parameter. Experiments show that it significantly improves processing results of mixed audio.